To ensure that the virtual machine objects continue to run smoothly during a rack failure, you can group hosts in different fault domains.
When you provision a virtual machine on the cluster with fault domains, vSAN distributes protection components, such as witnesses and replicas of the virtual machine objects across different fault domains. As a result, the vSAN environment becomes capable of tolerating entire rack failures in addition to a single host, storage disk, or network failure.
Prerequisites
- Choose a unique fault domain name. vSAN does not support duplicate fault domain names in a cluster.
- Verify the version of your ESXi hosts. You can only include hosts that are 6.0 or later in fault domains.
- Verify that your vSAN hosts are online. You cannot assign hosts to a fault domain that is offline or unavailable due to hardware configuration issue.